The present invention relates to a vehicle suspension system, and more particularly to a noise suppression device for coil springs.
Vehicle suspensions commonly include a coil spring at the front two and possibly all four wheels for supporting the vehicle body and frame. The springs isolate the body and frame from roadway shocks and undulations encountered by the wheels, so that occupants of the vehicle may ride in comfort while shock absorbing members dampen oscillations of the body on the springs.
Typical suspension springs must provide a stiffness or compressibility which is a compromise between a smooth ride and good vehicle handling while being mountable in a relative compact arrangement. The coil springs are therefore designed to operate with only a limited clearance between each convolution of the coil spring. In some instances, certain operating conditions may result in one convolution contacting another convolution. This contact can result in undesirable noise and reduced.
It is known to add an additional member such as a hose shaped sleeve on the coils to minimize noise during contact therebetween. Disadvantageously, the sleeve may be difficult to install.
Accordingly, it is desirable to provide a coil spring noise reduction member which is relatively uncomplicated and easy to install, and which guards against coil contact noise, while also isolating the spring from the contacting seat in the system.
The noise reduction assembly according to the present invention includes an isolator and a not necessarily annular noise guard extending therefrom. The isolator and the noise guard sandwich at least a portion of a first convolution of a vehicle suspension coil spring.
Applicant has determined that the majority of contact between the convolutions of the coil spring is generated by between approximately 1.0 and 1xe2x85x9c turns of the coil spring, i.e., between the first and second convolutions. The noise guard is aligned to the coil spring such that the noise guard extends between the first and second convolutions between approximately 1.0 and 1 xe2x85x9c turns of the coil spring to prevent contact in this area.
The present invention therefore provides an uncomplicated coil spring noise reduction assembly, which guards against the coil contact noise, and isolates the spring from transmitted noise.